//! `TelemetryStorage` — page metrics + passive vendor telemetry.
//!
//! Backends that don't aggregate telemetry inherit the no-ops; SQLite
//! writes `page_metrics` rows + `vendor_telemetry` for the P0-9 passive
//! signal pipeline.
use Url;
use crateResult;
/// Per-page metrics + passive vendor telemetry sink.